The Moore & Wright 891 Series Adjustable Depth Micrometer features interchangeable depth rods, with a 4mm diameter.
These adjustable depth micrometers conform to BS6468:1984.
Base Length: 63.5mm / 2.1/2in.
The Moore & Wright 891M150 Adjustable Depth Micrometer has the following specification:
Range: 0-150mm.
Resolution: 0.01mm.